Various embodiments relate generally to a semiconductor memory device and a method of operating the same.
Either non-volatile or volatile type of semiconductor memory devices utilizes a semiconductor material such as silicon Si, germanium Ge, gallium arsenide GaAs, indium phosphide InP, etc.
A volatile memory device would lose the stored data if power is not supplied. The volatile memory device includes a static RAM ‘SRAM’, a dynamic RAM ‘DRAM’, a synchronous DRAM ‘SDRAM’ and so on. A non-volatile memory device on the other hand retains the stored data even though power is not supplied. The non-volatile memory device includes a read only memory ‘ROM’, a programmable ROM ‘PROM’, an electrically programmable ROM ‘EPROM’, an electrically erasable and programmable ROM ‘EEPROM’, a flash memory, a phase-change RAM ‘PCRAM’, a magnetic RAM ‘MRAM’, a resistive RAM ‘ReRAM’, a ferroelectric RAM ‘FeRAM’, etc. Flash memory devices are gerally of a NOR or NAND type.
In recent, implementing a three-dimensional array structure in a semiconductor memory device has been an area of study to enhance its integrity and high integration.